In an electrophotographic image forming apparatus, there is known a process cartridge, in which an electrophotographic photosensitive drum and a process means that acts on the electrophotographic photosensitive drum are integrated into a cartridge, and the thus formed process cartridge is removably mounted to the apparatus main body. Then, in the color electrophotographic image forming apparatus for forming a color image, in which a plurality of colors are superimposed, the plurality of process cartridges for respective colors are used.
In the color electrophotographic image forming apparatus having a structure as described above, in which the plurality of process cartridges are removably mounted to the apparatus main body, there is known a structure in which a cartridge supporting member is movably provided with respect to the apparatus main body. Further, there is known one having a structure in which, under a state of supporting the plurality of process cartridges by the cartridge supporting member, the cartridge supporting member is inserted into the apparatus main body, or, is pulled out from the apparatus main body (U.S. Patent Application Publication No. 2007-0160380 A).